Blues produced a workmanlike performance at Ashton Gate to relegate Bristol City from the npower Championship.
Whilst Blues didn’t have to be at their best to overcome a downbeat City side, Birmingham still possessed too much quality.
There wasn’t too many clear-cut opportunities on a mild evening in Bristol, Wade Elliott’s first-half strike was enough to move his team up to 12th.
The visitors remained unchanged from Friday night’s draw at Leicester City and they soon took the lead on 16 minutes.
Once Jack Butland saved at the feet of Paul Anderson, after Paul Robinson’s slip allowed the winger in on goal, Blues advanced up the other end of the pitch – and Elliott placed Nathan Redmond’s cross into the bottom corner from 12-yards.
Blues were completely at ease for the rest of the half and rarely had to move out of first gear, with the Robins devoid of ideas.
Lee Clark’s men were happy to keep possession and had a second goal ruled out for offside, after Nikola Zigic mistimed his run.
City caused a moment of panic in the Blues box, however, when Steven Davies’ whipped ball across the face of goal evaded everyone.
The only other chance of the period arrived shortly before the interval, as the lively Redmond cut in from the right and saw a shot miss Tom Heaton’s near post by inches.
Sean O’Driscoll’s charges came racing out of the blocks at the start of the second-half, which was to be expected from a side that was 45 minutes away from relegation.
But having been played through by Davies, Sam Baldock was prevented from equalising by an outstretched Butland on 48 minutes.
Baldock would have been one-on-one with Butland again; if it wasn’t for Robinson’s perfectly-timed challenge on the former MK Dons forward.
Clark introduced some fresh legs off the bench in the form of Hayden Mullins and Chris Burke, but the Reds still had their moments, especially on 68 minutes as Davies’ knockdown was lashed narrowly wide by Baldock.
Birmingham went mightily close to putting City out of their misery in the final 10 minutes. Jack Butland’s long clearance found its way into the box via Redmond and Burke’s scuffed shot underneath Heaton was cleared off the line by Matthew Bates.
Baldock tested Butland from 20-yards before the game was out, but Blues comfortably held on to extend their impressive away record in 2013.